The Ossa-Morena Zone exposes distinct Ediacaran‒Fortunian successions that record the protracted evolution of an arc/backarc system developed onto the West African craton lithosphere in the ca. 700‒530 Ma timespan. The Ossa-Morena Zone was part of the Avalonian-Cadomian peri-Gondwanan arcs that developed by subduction of relics from the Neoproterozoic Mirovoi Ocean beneath the northern Gondwana margin during its amalgamation. Ossa-Morena actually represents the westernmost exposure of the Cadomian arc that extends eastward through Western, Central, and Eastern Europe up to Iran. Neoproterozoic rocks from the Ossa-Morena Zone include: (i) Cryogenian‒lower Ediacaran (ca. 690‒620 Ma) gneisses, thought to represent early arc rocks and/or their basement; (ii) ca. 610‒580 Ma mafic/ultramafic associations, interpreted as fore, intra and backarc ophiolites; (iii) a volcanosedimentary complex (Serie Negra Group), the most widely exposed, interpreted as the infill of the previously mentioned basins; and (iv) upper Ediacaran (ca. 580‒540 Ma) calc-alkaline and arc-tholeiite volcanic rocks and associated plutons, which suggest a secondary arc formed by antithetic subduction of a backarc basin beneath the Ossa-Morena Zone. The evolution of this part of the Cadomian arc involved intervals dominated by subduction and arc growth, alternating with phases dominated by extension, probably caused by slab roll-back, where arc collapse and basin formation took place, and phases dominated by compression, probably produced by flat-subduction, during which the preexisting rocks underwent deformation and metamorphism. Importantly, a major dextral strike-slip component appears to have taken place throughout most, if not all of the processes. History culminated with the oblique accretion of the Ossa-Morena Zone to the now adjacent Central Iberian Zone at ca. 540 Ma. The latter zone is considered to sit on Saharan Metacraton lithosphere, which documents an important dextral (eastward) displacement of the Ossa-Morena Zone along the Northwestern Gondwanan margin.